Lift jack



Nov. 28, 1961 J. w. ALLEN ETAL 3,010,698

LIFT JACK Filec}. April 14, 1960 2 Sheets-Sheet 1 ia M Nov. 28, 1961 J. W. ALLEN ETAL LIFT JACK Filed April 14, 1960 2 Sheets-Sheet 2 Wm W Jo/vz 77515572,

United States Patent 3,010,698 LIFT JACK John W. Allen and Westel E. Hawkins, La Grange, Ill.,

assignors to Stanray Corporation, Chicago, 111., a corporation of Delaware Filed Apr. 14, 1960, Ser. No. 22,368 13 Claims. (Cl. 2542) The present invention relates to lift jacks and particularly to pneumatic lift jacks adapted for lifting and moving heavy objects.

In railroad freight service there is being offered cornpartmentalized shipping facilities adapted to handle shipments corresponding to a fractional part of a railroad boxcar load. In one form of compartmentalized shipping, the facility is a shipping container which is carried locked in place on a railroad fiatcar. The shipping container may be of any convenient size and, in one example, may have a cubic capacity corresponding to one-half that of a railroad boxcar. According to best and most efficient usage, these containers are transferred from the flatcar in a railroad freight yard onto a truck bed and hauled to the warehouse or plant where the container can be directly loaded or unloaded, as the case may be, or transferred from the truck bed to the shipping dock to await the convenience of the shipper.

Some of the efliciency and the attendant economic savings to be derived from this type of shipping operation are lost when it is necessary to employ cranes or other special heavy equipment for effecting transfer of the containers between the flatcar, the truck bed and the shipping dock. Nor is this loss of efficiency to be avoided by providing each container with motive means because such means are generally expensive and complicated, subjeet to damage because of the severe handling to which these units are subjected, and are utilized only infrequently during the transport life of the unit. Accordingly, to complement the efficiency of this type of shipping operation there is a need for a simple and rugged device for easily and conveniently effecting transfers of such shipping containers.

It is a general object of the present invention to provide a jack of a simple and rugged construction which can be easily utilized for lifting and effecting the transfer of heavy objects.

An additional object of the invention is to provide an improved mobile jack of a simple and rugged construction having a low silhouette adapted to fit between stacking blocks or supporting stubs and capable of lifting heavy objects supported thereby.

A more specific object of the invention is to provide an improved mobile pneumatic lift extendable in a vertical direction and supported on a plurality of rollers distributed over a large area by means of which heavy objects can be lifted and easily moved over discontinuous surfaces.

It is a further object of the invention to provide an improved mobile lift supported on a plurality of rollers mounted in a hinged base channel member and extendable in a vertical direction therewith, to more readily enable the transfer of containers between vehicles having a difference in elevation.

Additional objects and features of the invention pertain to the particular structure and arrangements thereof whereby the above identified objects are achieved. The invention, both as to its structure and method of operation, will be better understood by reference to the following specification and drawings, forming a part thereof, wherein:

FIGURE 1 is a front view of a heavy object supported iceon a pair of mobile pneumatic lifts in accordance with the invention;

FIGURE 2 is a partial cross-section view taken along lines 2-2 of FIGURE 1;

FIGURE 3 is a partial cross-sectional view of the mobile pneumatic lift in accordance with the invention;

FIGURE 4 is a lateral cross-sectional view of the lift in its retracted condition;

FIGURE 5 is a lateral cross-sectional view of the lift in its extended position;

FIGURE 6 is a side elevational view of a modified form of base member embodying the invention;

FIGURE 7 is an enlarged side elevational view of the hinge structure of FIGURE 6; and

FIGURE 8 is a top plan view of FIGURE 7.

This application is a continuation-in-part of our previously filed application, Serial No. 714,154, filed February 10, 1958, now abandoned.

Considering now the structure of the mobile pneumatic lift in accordance with the invention and referring first to the modification shown in FIGURES 1 to 5 inclusive of the drawings, there is shown a lift unit 10 made up of an inverted base channel member 11, a plurality of rollers 15 supported within the channel 11, an inflatable bag 20 carried on the base channel member 11, a cover plate or channel member 25 supported on the inflatable bag 20 and overlying the base channel member 11, and hinge guides 35 joining the base channel member 11 to the cover channel member 25.

The base channel member 11 is closed at both its ends and is provided with a continuous flange 12 extending outwardly from the lip of the channel member to provide a bumper surface for the lift unit. The rollers 15 are spaced apart within the cavity of the base channel 11 and each roller is supported between the side walls 11a and 11b by means of an axle 16 with at least a portion of the roller projecting below the channel member 11 and the flange 12 thereof.

. Each roller 15 may be of a hollow cylindrical configuration provided with roller bearings at the ends thereof, it may be of solid configuration bored to receive the axle 16 thereof, or it may be a casting for which the axle portions 16 are an integral part.

The inflatable bag 20 is carried on the upper wall of the base channel 11 and is preferably of a heavy cloth material coated with a sealer such, for example, as a nylon cloth bag coated with neoprene. In its deflated condition, as shown in FIGURE 4, the inflatable bag 20 overlaps the side walls 11a and 11b of the channel member 11 and extends not beyond the outer edge of the flange 12 thereof. In its expanded condition, as shown in FIGURES 3 and 5, the inflatable bag 20 is extended in a vertical direction so as to remove its flexible walls from association with the side walls 11a and 11b of the base channel 11 and to be supported entirely on the upper wall 110 thereof. 7

Overlying the base channel 11 and the inflatable bag 20 carried thereon is the cover channel member 25 having dimensions slightly larger than those of the base channel member 11 so as to accommodate a telescoping action therebetween. Preferably the junctures between the side walls 25a and 25b and the upper wall 25c assume an arcuate form so as to provide a better contact surface between the inflatable bag and the cover channel member 25. As shown in FIGURE 4, when the bag 20 is deflated the cover channel member 25 is supported on the base channel member 11 by means of the collapsed side walls of the bag 20.

It is to be noted that the inflatable bag 20 is substantially rectangular in cross-section so that as it is inflated pressures built up in the bag are exerted essentially be tween the top wall 110 of the base member 11 and the top wall 25c of the cover channel member 25 so as to cause the latter to rise vertically and extend itself from the base channel member 11. To facilitate inflation and deflation of the bag 20 a conduit 26 is provided which extends through the bag 20 and the end wall 25d of the cover channel 25. The conduit 26 has connected thereto a selectively operative two-way valve 28 of any suitable type which is connectable to an air compressor unit not shown.

To provide lateral and longitudinal stability to the pneumatic lift particularly in its extended position, there is provided at its ends, as shown in FIGURE 2, hinged guides 35. As shown in detail in FIGURE 3, the guide 35 is made up of two arms 36 and 37. each joined at one end thereof by means of a hinge 38. The other end of the arm '36 is joined to a flange extension 27 of the end wall 25d of the cover channel 25 by means of a bolt 39 or any other suitable means. The free end of the arm 37 is joined by means of a hinge 45 to the end wall 11d and the flange 12 of the base channel 11. The guide 35 is of a rigid structure so that it accommodates movement only in the vertical direction. Accordingly, when the lift is in its extended position, the cover channel member 25 is held in alignment over the base channel member 11 and is prevented from any shifting movement with regards thereto.

Referring now to the modification shown in FIGURES '6 to 8 inclusive of the drawings, there is here shown a modified form of lift mechanism comprising essentially longitudinally aligned hinged base channel members 50 50, joined together in end to end relationship by the hinge structure 52. The thus joined channel members 50 are substantially identical with the base member 11 of the former modification, but, being hinged, provide considerable flexibility in traveling from one platform to another at a slightly different elevation.

The inflatable bag rests upon the upper surface ofthe base member 50 between it and the cover channel memer as in the former modification.

The'rollers 56 are mounted in flanges 54 depending at spaced intervals from the side flanges of the base channels 50 and are mounted so that the periphery of the rollers project below the edge of the mounting flanges 54. The hinge structure is what may be termed a double hinge consisting. of two parallel hinge pintles 58 and 69 which are joined together by a hinge plate '62 having two sets of three ears 64 curled around the pintles 58 and 60. The'top walls 50b of the base channels 5050 are each provided with a set of two ears 6666, each set curled around the adjacent pintle. It is thus apparent that each of thev base sections SO-can rotate about the axis of either or both of the pintles 58 and 60 when the transfer device is traversing from one platform to another at a slightly different elevation.

Considering now the manner in which the mobile pneumatic lifts in accordance with the invention are employed, and referring specifically to FIGURES l and 2, there is shown therein a body 49, representative of a shipping container, provided With a detent 41 in the lower surface thereof of a height sufiicient to receive the retracted lifts 10. As the lifts 10 are inflated in a manner as described, the cover channel member 25 contacts the bottom wall 42 of the container and lifts the container fromcontact with the surface 43. Assuming that the surface 43 is representative'of a truck bed of a motor transport and that the shipping container 40 is to be moved onto a platform 44 which is representative of the bedof a railroad flatcar, a cable 46 associated with a winch 47 is connected to the supported shipping container 40 at a lug 48 so that as the cable 46 is drawn up on the winch 47 the container '40, riding on. the rollers of the lifts, rolls across the surfaces 43 and 44 bridging the discontinuity therebetween. Accordingly, the shipping container '40 may be conveniently positioned on the 4 platform 44 and thereafter the lifts 10 deflated to support the shipping container directly on the surface 44. The lifts 10 are then removed from under the shipping container and made available for other uses.

While the invention has been described in terms of a lift adaptable for lifting and moving shipping containers, it is appreciated that such lifts can enjoy general utility in any heavy lifting operation. Additionally, it is appreciated that the lifts can be inverted from their described position so that the roller surfaces 15 are faced upward to make contact with any object to be lifted. Such usage might be particularly well suited to an arrangement where roller tracks are employed for further movement of the heavy object after it has been lifted from its supported position.

It may be desirable to glue the bag 20 to the cover plate member 25, and the base channel member 11 along the opposite longitudinal center lines of said members, so as to position the bag correctly relative thereto. If the members are correctly positioned relative to each other, the air pressure can only cause relative vertical movement of said members.

The improvement in the modification shown in FIG- URES 6 to 8 is in the provision of hinge means for the base channel of the lift mechanism to enable it to traverse from one level to another without trouble, and the inflatable bag compensating therefor.

While the embodiments described herein are at present considered to be preferred, it is appreciated that variations and'modifications maybe made therein. Accordmgly, it is intended to cover in the appended claims all such modifications and variations as fall within the true spirit and scope of the invention;

I claim:

1. A jack'fo'rlifting and moving heavy objects, comprising an elongated inverted base channel member with its open face downward, a plurality of rollers carried within said channel member and depending below the flanges of said channel member for facilitating relative movement between said channel member and other bodies, an elongated cover channel plate member overl-y ng said base channel member, an expandable contamer carried between the outer surface of said channel member and said plate member and coextensive therewith, and means for expanding said container, whereby responsive to the expansion of said container forces are exerted between said base channel member and said cover plate member for causing extending movement therebetween.

2 A jack for lifting and moving heavy objects, comprising an elongated inverted base channel member with its open face downward, a plurality of rollers carried transversely within said channel member spaced apart one from another and depending below the flanges of said channel member for facilitating relative movement between said channell member and other bodies, a channel plate member at the outer surface of and overlying said channel member, means joining the ends of said channel member and said plate member on a transverse axis for guiding relative movement therebetween, an inflatable container carried between the outer surface of said channel base member and said plate member, and means for inflating said container, whereby responsive to the inflation of said container forces are exerted between said channel member and said plate member for causing extending movement therebetween.

3. 'A jack for lifting and moving heavy objects, comprising an elongated base channel member with its open face downward, a plurality of axles journalled at opposite ends in the side walls of said base channel member, rollers carried upon said axles within said channel member, said rollers being spaced apart one from another and extending below the side flanges of said channel member for facilitating relative movement between said channel member and other bodies, a cover channel plate member having slightly larger dimensions than the base channel member at the outer surface of and overlying said base channel member, hinge means joining the ends of said channel member and said plate member on a transverse axis for permitting only perpendicular movement therbetween, an inflatable container carried between the outer surface of said channel member and said plate member, and means for inflating said container, whereby responsive to the inflation of said container forces are exerted between said channel member and said plate member for causing extending movement therebetween.

4. A jack for lifting and moving heavy objects, comprising a base channel member closed at its ends, a plurality of rollers carried transversely within and journalled at opposite ends in the side walls of said base channel member spaced apart one from another and extending below the side flanges thereof for facilitating relative movement between said channel member and other bodies, a channel plate member overlying at least a portion of the outer surface of said channel member, hinged means joining said channel member and said plate member on a transverse axis for permitting only reversible extending movement therebetween, an inflatable container carried between the outer surface of said channel member and said plate member, and means for inflating said container whereby responsive to the inflation of said container forces are exerted between said channel member and said plate member for causing extending movement therebetween.

5. A jack for lifting and moving heavy objects, comprising a first channel member closed at its ends and inverted with its open face downward, a plurality of rollers carried within said first channel member between the side flanges thereof spaced apart one from another, said rollers depending below the flanges thereof for facilitating movement of said first channel member, a second channel member overlying said first channel member, hinged means joining said first channel member and said second channel member for permitting only vertical movements therebetween, an inflatable bag carried on said first channel member interlying said first and second channel members and supporting in a deflated condition said second channel member in overlapping relation with said first channel member, and means for inflating said bag, whereby responsive to inflation of said bag forces are exerted between said first and second channel members for extending said second channel member vertically from overlapping relation with said first channel member.

6. A jack for lifting and moving heavy objects, comprising a first channel member closed at its ends and inverted with its open face downward, a flange extending outwardly from the side flanges of said first channel member, a plurality of rollers carried within said first channel member between the side flanges thereof spaced apart one from another and extending below said side flanges for facilitating movement of said first channel member, a second channel member overlying said first channel member, hinged means joining the ends of said first channel member and said second channel member for permitting only vertical movements therebetween, an inflatable bag carried on the outer Surface of said first channel member, said inflatable bag in a deflated condition overlapping the top and side walls of said first channel member and supporting said second channel member in overlapping relationship with said first channel member, and means for inflating said bag, whereby forces are exerted between said first channel member and said second channel member for extending said second channel member vertically from overlapping relation with said first channel member.

7. A mobile pneumatic jack for lifting and moving heavy objects, comprising a first longitudinally extending channel member closed at its ends and inverted with its open face downward, said first channel member including a continuous flange extending outwardly from the bottom of the side flanges of said first channel member, a plurality of rollers carried within said first channel member between the side flanges thereof spaced apart one from another, said rollers extending below said continuous flange for facilitating movement of said first channel member, a second longitudinally extending channel member closed at its ends overlying said first channel member, hinged means joining said first and second channel members at the respective ends thereof for permitting only vertical movements therebetween, a longitudinally extending inflatable bag carried on said first channel member, said inflatable bag in a deflated condition overlapping the outer surface of said first channel member to the flange portion thereof and supporting said second channel member in overlapping relationship with said first channel member, and means for alternately inflating and deflating said bag, whereby responsive to inflation of said bag forces are exerted between said first channel member and said second channel member for extending said second channel member vertically from overlapping relation with said first channel member thereby to lift any heavy objects contacted by said second channel member in said extending movement.

8. The mobile pneumatic jack set forth in claim 7 wherein said second channel member is formed in arcuate contours at junctures between wall portions thereof for better accommodating the support provided by said inflatable bag.

9. A jack for lifting and moving heavy objects, comprising an elongated inverted base channel member facing downward, a plurality of spaced apart rollers carried transversely within and journalled to the side flanges of said base channel member, said rollers depending below the flanges of said base channel for facilitating movement of said base channel over a supporting surface, an elongated inverted channel cover plate member telescopically arranged over said base channel member, said base channel member and channel cover plate having closed ends, hinge means joining the ends of the base channel member and cover plate on a transverse axis, an elongated expandable container carried between said base channel member and said cover plate member, means for expanding the container, whereby responsive to the expansion of the container forces are exerted between said base channel member and said cover plate member for causing extending movement therebetween.

10. The structure of dlaim 9 and means whereby said expandable container is fastened along opposite longitudinal center lines to said channel member and said plate member.

11. The structure of claim 9 wherein the base channel member is formed of a plurality of hingedly united sections to facilitate traverse of said jack over uneven surfaces.

12. A narrow elongated jack for lifting and moving heavy objects, comprising hingedly united longitudinally alined base channel members facing downward, a plurality of longitudinally spaced transverse rollers carried within said base channel members and depending below the flanges of said channel members for facilitating relative movement between said base channel members and other bodies, an elongated cover channel member overlying said base channel members, an expandable container interlying said base channel members and said cover channel member, and means for expanding said container, whereby responsive to the expansion of said container forces are exerted between said base channel members and said cover channel member for causing extending movement therebetween.

13. A narrow elongated jack for lifting and moving heavy objects, comprising longitudinally alined, hingedly united base channel members, a plurality of transversely disposed rollers carried within said channel members longitudinally spaced apart one from another and depending below said base channel members for facilitating movement of said base channel members over uneven surfaces, a cover channel member overlying said base channel members, means associated with said base channel members and said cover channel member for guiding a path of movement therebetween, an inflatable container 'interlying said base channel members and said cover channel member, and means for inflating said con- 10 2,070,960

t ainer, whereby responsive to the inflation of said container forces are exerted between said channel members and said cover channel member for causing extending movement t-herebetween.

References Cited in the file of this patent UNITED STATES PATENTS Patterson May 21, 1935 Phillips Feb. 16, 1937 

